Transconjunctival botulinum toxin injection into the lacrimal gland in crocodile tears syndrome.

Purpose: To determine the efficacy and safety of botulinum toxin injection into the lacrimal gland as a symptomatic treatment of crocodile tear syndrome (CTS).

Methods: Our study included six patients of unilateral gustatory hyper lacrimation following either an episode of facial paralysis or post trauma or any related surgery that posed a risk of damaging the facial nerve. Detailed history regarding previous trauma, duration of facial paralysis, previous significant surgery, and duration of steroid use following facial paralysis was noted. Schirmer's test was done at baseline and 3 months follow-up. Patients' consent was taken prior to treatment with botulinum toxin injection in the lacrimal gland. Repeat injection of 5 U botulinum toxin (type A) was administered into the lacrimal gland of all patients transconjunctivally within an interval of 1 week. All patients were followed up with Schirmer's test at 6 weeks and 3 months. Any complications during treatment were recorded.

Results: All six patients showed complete or partial disappearance of reflex lacrimation while chewing following botulinum injection measured by a significant reduction in Schirmer's value. When comparing Schirmer test values before (27.8 ± 3.58 mm) and after (11.6 ± 2.28 mm) BTX-A injection, the differences observed (P = 0.002) were statistically significant (P < 0.05). Only two patients developed mild transitory ptosis. No other complications were noted.

Conclusion: Transconjunctival botulinum toxin injection into the lacrimal gland is an effective and safe method to decrease reflex lacrimation during eating or chewing in CTS or gustatory hyper-lacrimation syndrome.